Consumers who may be leery of committing to the purchase or lease of a plug-in or battery-electric car might be lured to a subscription that lets them test out a vehicle with less long-term commitment.

The first subscription-based ownership models from Cadillac and Porsche provide on-demand service, and subscribers can swap out vehicles simply by scheduling a change.

Navigant Research believes this could sway more consumers to choose an electric car since, realistically, they're not making much of a commitment to a particular car.

Some other subscription services, including Care by Volvo, require the subscriber to hold onto the car for only a year, less than the usual three-year commitment for an affordable lease rate.

The subscription model remains far from perfect. The high monthly payment is better suited to more premium brands, which lets a carmaker bake in service, insurance, white-glove delivery, and even regular detailing services.

For example, the least expensive tier of Porsche's Passport subscription service is $2,000 per month—hardly affordable for the average car buyer.

In fact, Volvo is working on an ecosystem in which subscribers could share their car with designated friends and family, too.

Even if batteries and associated electric-car technology remain more expensive than traditional internal-combustion engines, a flat subscription fee could be what the market needs for more consumers to embrace electrification.